Traditional or conventiinal product
If place for a year with rate 4% Fixed deposit. 4% rate will  be locked in irrespective OPR moving up or down in that 12 months period

Traditional step up product ( FD rate stepped up by quarterly)
FD rate steppng upwards quarterly. Bank will pay as per the advertisement irrespective OPR moving up and down thoughout the 12 month period.
Public Bank new FD step up FD product,
Public bank specifically mentioned in their brochure and contract agreement that the step up interest rate may not be followed should there be a change in OPR.
Meaning suppose a person has taken up a step up FD for 12 months period. Initially the second quarter period stated  is 3.5% but Bank Negara has revised OPR downwards by .25%, Public bank has the right to revise downward the step up FD rate promised earlier even though the FD placement is for a year and still in the running.

The reverse could be true when BNM raises the OPR. So far Public bank has not yet revised the step up rate since OPR has been remained unchanged.

Bottom line is do watch on the clause and do not think the bank cannot change the FD rate after a person has placed the FD for a long period.

how much sales charge was the ASNB UT? 4%?

Cannot go for it just because of the FD promo. Has to be wanted to invest in ASNB then go for it to get the FD promo as well. 
If you go for the FD/ASNB bundle, the sales charge is still 5% plus GST. Not 2% rebate. I paid 5% with GST for the FD/ASNB bundle in April.